Agent of the Shadow Thieves

Commander creatures you own have "Whenever this creature attacks a player, if no opponent has more life than that player, put a +1/+1 counter on this creature. It gains deathtouch and indestructible until end of turn."

Soul Search

Target opponent reveals their hand. You choose a nonland card from it. Exile that card. If the card's mana value is 1 or less, create a 1/1 white and black Spirit creature token with flying.

Watery Grave

({T}: Add {U} or {B}.)
As Watery Grave enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Psychic Barrier

Counter target creature spell. Its controller loses 1 life.

Quench

Counter target spell unless its controller pays {2}.

Faerie Mastermind

Flash
Flying
Whenever an opponent draws their second card each turn, you draw a card.
{3}{U}: Each player draws a card.

Deserted Beach

Deserted Beach enters the battlefield tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Zur the Enchanter

Flying
Whenever Zur the Enchanter attacks, you may search your library for an enchantment card with mana value 3 or less, put it onto the battlefield, then shuffle.

Mana Leak

Counter target spell unless its controller pays {3}.

Glacial Fortress

Glacial Fortress enters the battlefield tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Isolated Chapel

Isolated Chapel enters the battlefield tapped unless you control a Plains or a Swamp.
{T}: Add {W} or {B}.

Windswept Heath

{T}, Pay 1 life, Sacrifice Windswept Heath: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.

Diplomatic Immunity

Enchant creature
Shroud (A permanent with shroud can't be the target of spells or abilities.)
Enchanted creature has shroud.

Invasive Surgery

Counter target sorcery spell.
Delirium — If there are four or more card types among cards in your graveyard, search the graveyard, hand, and library of that spell's controller for any number of cards with the same name as that spell, exile those cards, then that player shuffles.

Counterspell

Godless Shrine

({T}: Add {W} or {B}.)
As Godless Shrine enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Force of Will

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost.
Counter target spell.

Lofty Denial

Counter target spell unless its controller pays {1}. If you control a creature with flying, counter that spell unless its controller pays {4} instead.

Stubborn Denial

Counter target noncreature spell unless its controller pays {1}.
Ferocious — If you control a creature with power 4 or greater, counter that spell instead.

Underground Sea

Scalding Tarn

{T}, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Force Spike

Counter target spell unless its controller pays {1}.

Force of Negation

If it's not your turn, you may exile a blue card from your hand rather than pay this spell's mana cost.
Counter target noncreature spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Countersquall

Counter target noncreature spell. Its controller loses 2 life.

Wizard's Retort

This spell costs {1} less to cast if you control a Wizard.
Counter target spell.

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Daybreak Coronet

Enchant creature with another Aura attached to it
Enchanted creature gets +3/+3 and has first strike, vigilance, and lifelink. (Damage dealt by the creature also causes its controller to gain that much life.)

Rebuff the Wicked

Counter target spell that targets a permanent you control.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Dispel

Scatter Ray

Counter target artifact or creature spell unless its controller pays {4}.

Obscura Storefront

When Obscura Storefront enters the battlefield, sacrifice it. When you do, search your library for a basic Plains, Island, or Swamp card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

All That Glitters

Enchant creature
Enchanted creature gets +1/+1 for each artifact and/or enchantment you control.

Ghostly Prison

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Gemstone Caverns

If Gemstone Caverns is in your opening hand and you're not the starting player, you may begin the game with Gemstone Caverns on the battlefield with a luck counter on it. If you do, exile a card from your hand.
{T}: Add {C}. If Gemstone Caverns has a luck counter on it, instead add one mana of any color.

Curious Obsession

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, you may draw a card."
At the beginning of your end step, if you didn't attack with a creature this turn, sacrifice Curious Obsession.

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Disrupt

Counter target instant or sorcery spell unless its controller pays {1}.
Draw a card.

Marsh Flats

{T}, Pay 1 life, Sacrifice Marsh Flats: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.

Judge's Familiar

Flying
Sacrifice Judge's Familiar: Counter target instant or sorcery spell unless its controller pays {1}.

Shipwreck Marsh

Shipwreck Marsh enters the battlefield tapped unless you control two or more other lands.
{T}: Add {U} or {B}.

Bloodstained Mire

{T}, Pay 1 life, Sacrifice Bloodstained Mire: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Darkslick Shores

Darkslick Shores enters the battlefield tapped unless you control two or fewer other lands.
{T}: Add {U} or {B}.

Permission Denied

Counter target noncreature spell. Your opponents can't cast noncreature spells this turn.

Verdant Catacombs

{T}, Pay 1 life, Sacrifice Verdant Catacombs: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Pilfer

Target opponent reveals their hand. You choose a nonland card from it. That player discards that card.

Concealed Courtyard

Concealed Courtyard enters the battlefield tapped unless you control two or fewer other lands.
{T}: Add {W} or {B}.

Imprisoned in the Moon

Enchant creature, land, or planeswalker
Enchanted permanent is a colorless land with "{T}: Add {C}" and loses all other card types and abilities.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Miscast

Counter target instant or sorcery spell unless its controller pays {3}.

Dread Fugue

Cleave {2}{B} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Target player reveals their hand. You choose a nonland card from it [with mana value 2 or less]. That player discards that card.

Blue Elemental Blast

Choose one —
• Counter target red spell.
• Destroy target red permanent.

Tale's End

Counter target activated ability, triggered ability, or legendary spell.

Flooded Strand

{T}, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Island

Lay Bare the Heart

Target opponent reveals their hand. You choose a nonlegendary, nonland card from it. That player discards that card.

Turn Aside

Drowned Catacomb

Drowned Catacomb enters the battlefield tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Daze

You may return an Island you control to its owner's hand rather than pay this spell's mana cost.
Counter target spell unless its controller pays {1}.

Wash Away

Cleave {1}{U}{U} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Counter target spell [that wasn't cast from its owner's hand].

Mana Tithe

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Stifle

Counter target activated or triggered ability. (Mana abilities can't be targeted.)

Lose Focus

Replicate {U} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Counter target spell unless its controller pays {2}.

Command Tower

Inquisition of Kozilek

Target player reveals their hand. You choose a nonland card from it with mana value 3 or less. That player discards that card.

Raffine's Tower

({T}: Add {W}, {U}, or {B}.)
Raffine's Tower enters the battlefield tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Dawn Charm

Choose one —
• Prevent all combat damage that would be dealt this turn.
• Regenerate target creature.
• Counter target spell that targets you.

Change the Equation

Choose one —
• Counter target spell with mana value 2 or less.
• Counter target red or green spell with mana value 6 or less.

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Seachrome Coast

Seachrome Coast enters the battlefield tapped unless you control two or fewer other lands.
{T}: Add {W} or {U}.

Hydroblast

Choose one —
• Counter target spell if it's red.
• Destroy target permanent if it's red.

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Thought Erasure

Target opponent reveals their hand. You choose a nonland card from it. That player discards that card.
Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Mental Misstep

({U/P} can be paid with either {U} or 2 life.)
Counter target spell with mana value 1.

Memory Lapse

Counter target spell. If that spell is countered this way, put it on top of its owner's library instead of into that player's graveyard.

Swamp

Arid Mesa

{T}, Pay 1 life, Sacrifice Arid Mesa: Search your library for a Mountain or Plains card, put it onto the battlefield, then shuffle.

Shielded by Faith

Enchant creature
Enchanted creature has indestructible.
Whenever a creature enters the battlefield, you may attach Shielded by Faith to that creature.

Dismal Backwater

Dismal Backwater enters the battlefield tapped.
When Dismal Backwater enters the battlefield, you gain 1 life.
{T}: Add {U} or {B}.

Tranquil Cove

Tranquil Cove enters the battlefield tapped.
When Tranquil Cove enters the battlefield, you gain 1 life.
{T}: Add {W} or {U}.

Mystical Dispute

This spell costs {2} less to cast if it targets a blue spell.
Counter target spell unless its controller pays {3}.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Flusterstorm

Counter target instant or sorcery spell unless its controller pays {1}.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Negate

Plains

No More Lies

Counter target spell unless its controller pays {3}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Swan Song

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

Tundra

Mana Breach

Whenever a player casts a spell, that player returns a land they control to its owner's hand.

Envelop

Scrubland

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.